U.S. patent number 7,926,238 [Application Number 10/754,323] was granted by the patent office on 2011-04-19 for stab-in connector.
This patent grant is currently assigned to Worthington Armstrong Venture. Invention is credited to Yu Lin, William J. Platt, Brett W. Sareyka.
United States Patent |
7,926,238 |
Sareyka , et al. |
April 19, 2011 |
Stab-in connector
Abstract
A stab-in connector that locks with an opposing identical
connector, through a slot in the main beam of a suspended ceiling
grid. The connector has a straight locking latch that is
cantilevered from a bend at a base of the connector. The bend is in
the form of an arc. The bend forms a pivot for the latch. Contact
between the cantilevered straight locking latch and the side of the
slot is delayed as the connector is being stabbed into the slot.
During the delay, the connectors are positioned within the slot,
and relative to each other, so that substantially less force is
needed than the force that was necessary to engage prior art
stab-in connectors into locking position.
Inventors: |
Sareyka; Brett W. (West
Chester, PA), Lin; Yu (Blue Bell, PA), Platt; William
J. (Aston, PA) |
Assignee: |
Worthington Armstrong Venture
(Malvern, PA)
|
Family
ID: |
34592600 |
Appl.
No.: |
10/754,323 |
Filed: |
January 9, 2004 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20050166509 A1 |
Aug 4, 2005 |
|
Current U.S.
Class: |
52/506.06;
52/506.09; 52/506.07; 52/506.1 |
Current CPC
Class: |
E04B
9/068 (20130101); E04B 9/125 (20130101) |
Current International
Class: |
E04B
9/10 (20060101); E04B 9/34 (20060101) |
Field of
Search: |
;52/506.01,506.05,506.06,506.07,506.08,506.09,506.03,506.04,506.1,512 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
See attached European Patent Office Action, dated Oct. 5, 2006, in
European Patent Application No. 04026847.6. cited by other .
See attached Response, dated Nov. 30, 2006, to European Patent
Office Action dated Oct. 5, 2006. cited by other .
See attached copy of Letters Patent for New Zealand Patent No.
536057, granted Oct. 12, 2006, titled Stab-in Connector. cited by
other .
See attached European Patent Office Action, dated Mar. 2, 2007, in
European Patent Application No. 04026847.6. cited by other .
See attached Response, dated Apr. 10, 2007, to European Patent
Office Action dated Mar. 2, 2007. cited by other .
See Attached Copy of European Search Report Issued by European
Patent Office on May 31, 2006 in European Patent Application No.
04026847.6. cited by other.
|
Primary Examiner: Chapman; Jeanette E.
Attorney, Agent or Firm: Chovanes; Eugene
Claims
What is claimed is:
1. In a suspended ceiling grid connection, a connector-to-connector
lock between opposing first and second identical connectors, each
on the end of a cross beam, that extend through a slot in a main
beam from opposite directions, with a cantilevered locking latch
extending from a base in each such first and second identical
connectors capable of forcing the connectors into locking contact
with each other within the slot; the improvement comprising: a
cantilevered locking latch extending in a curve before extending in
straight line fashion, wherein the curve is capable of delaying
forced contact of a second identical connector being stabbed
through the slot with an opposing first identical connector already
in the slot, whereby the second identical connector is capable of
being adjusted vertically without being forced against the first
identical connector already in the slot by the locking latch in
contact with a side of the slot.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
Suspended ceilings are used extensively in commercial and
industrial buildings. In such ceilings, a metal grid framework of
interconnected main beams and cross beams is hung from a structural
ceiling by wires. The grid supports acoustical panels in
rectangular openings formed in the grid.
This invention relates to the connectors used in the grid to join a
pair of opposing cross beams and a main beam at grid
intersections.
2. Prior Art
Suspended ceilings having metal beams interconnected into a grid
that supports panels are well known. U.S. Pat. Nos. 5,839,246 and
6,178,712, for instance, incorporated herein by reference, show
such ceilings.
The grid in such ceilings has, at each grid intersection, a pair of
opposing cross beams and a main beam that form a connection.
The present invention relates to such a connection.
Each cross beam in such a connection has a connector at its end
that is thrust, or stabbed-in, from opposing sides of the main
beam, through a slot in the main beam. The connectors are all
identical.
The connector that is first inserted into the slot is prevented
from being withdrawn back out of the slot by the cantilevered latch
in the connector, in the form of a pivoted flexible leaf spring.
Such latch, which is integral with the connector base and formed
therefrom by punching, is biased toward an open position. The
latch, which is cantilevered at an angle from the base of the
connector, flexes toward a closed position under the restraint of
the side of the slot when the connector is stabbed through the slot
to make the connection, but which then reflexes back to its biased
rest position to prevent withdrawal of the connector back out of
the slot.
Another connector on an opposing cross beam, identical to the first
connector thrust through the slot, is then stabbed through the slot
in the reduced space in the slot alongside the first. The latch on
the connector contacts the side of the slot close to the latch
pivot, and is flexed toward a closed position.
In inserting particularly the second connector into the slot, with
a linear stab-in motion, substantial work and force are necessary
to make the connection.
This resistance arises virtually immediately as the second
connector into the slot enters the slot, and continues throughout
the travel of the connector until it is seated in a locked
position, as described below, with the first connector into the
slot.
Both connectors interconnect when the second connector into the
slot is fully inserted. Detents formed from the connector base, in
the form of bulbs, that have a cam side and a locking side, and the
ends of the connectors, flex and reflex to engage in what is
sometimes referred to as a connector-to-connector lock, or
"handshake" lock. Such a "handshake" connection between the
connectors prevents the connectors from being pulled apart lineally
out of the slot. The connectors are kept laterally and vertically
together by the slot in the main beam.
In the seated locked position, the second connector is horizontally
aligned with the first connector within the confines of the slot,
so that the locking detents on the connectors are engaged and
retained at the same level to form the connector-to-connector lock.
Generally, the second connector must be either elevated or
depressed as it passes into the slot to achieve such horizontal
alignment. Hence, the profile of the leading edge of the connector
is tapered to guide the connector during its travel though the main
beam slot.
Such connectors are well known in the prior art and are disclosed,
for instance, in the above referred to patents.
Numerous such connections must be made to create a ceiling
grid.
SUMMARY OF THE PRESENT INVENTION
The prior art stab-in connector described above is improved so that
it takes much less force, and less work, to make the
connection.
There is less work and less force necessary, because, in inserting
the second connector into the reduced area of the slot of the main
beam, (1) there is a delay in the contact between the locking latch
and the side of the slot, so that during the delay, (2) elements in
the ensuing connection are positioned while offering the least
resistance from frictional forces to such positioning, and (3) when
contact between elements does occur, the elements are positioned to
offer the least resistance to making a connection.
To achieve the above, the locking latch, which in its unflexed
position, must extend laterally far enough out from the base of the
connector to prevent withdrawal of the first connector through the
slot before the second connector is inserted, is pivoted from the
connector base in an arc, rather than in an acute bend as in the
prior art.
This, as set forth in (1) above, delays contact between the latch
and the side of the slot, when the second connector is inserted
into the slot and, as set forth in (2) above, such contact is made
further out along the latch from the pivot point, closer to the end
of the latch, creating a longer lever arm, so that less force is
needed to close the latch.
The outward end of the locking latch in an unflexed position,
extends to the same position as the prior art straight latch
pivoted at a sharp, acute angle. This position is necessary, so
that the connector cannot be withdrawn after the latch passes
through the slot.
Also, during the delay in (1) above, the second connector into the
slot is being positioned vertically by the taper on the leading end
of the connector, which engages either the top or bottom of the
slot, to the same horizontal level as the first connector, without
frictional resistance created in the connection of the prior art,
where the locking latch, virtually immediately, forces the first
and second connection laterally together.
By adjusting the second connector into the slot more quickly
vertically as it travels through the slot, the locking detents and
connector ends that engage together by flexing, are in a position,
as set forth in (3) above, to offer the least resistance to such
engagement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a right side elevational of a connection of two cross
beams through a slot in the main beam, showing the connectors of
the invention engaged in a connector-to-connector lock.
FIG. 2 is a right side elevational view of the connector of the
invention, shown in the connection of FIG. 1.
FIG. 2a is a top sectional view of the connector of the invention,
taken on the line A-A of FIG. 2, with an enlarged circled portion
showing the latch of the invention.
FIGS. 3 and 3a are views of a prior art corresponding to the views
of FIGS. 2 and 2a.
FIG. 3 is a side elevational view of a prior art connector.
FIG. 3a is a top sectional view of a prior art connector taken on
the line A-A of FIG. 3, with an enlarged circled portion showing a
prior art latch.
FIG. 4 is a group of graphs, 4a, 4b, and 4c which represent the
forces involved in making a connection.
FIG. 4a is a graph of the force necessary to overcome resistance in
making the connection of the prior art.
FIG. 4b is a graph of the force necessary to overcome resistance in
making the connection of the invention.
FIG. 4c is a graph of the forces represented in 4a and 4b,
overlapped.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The Prior Art
U.S. Pat. No. 5,839,246, incorporated herein by reference, is
representative of the prior art connection which is improved by
this invention. The connection itself, and the method of making
such connection, is set forth in detail in the '246 patent.
In the present drawings, a connection of the invention is shown in
FIGS. 1, 1a, with the improvement of the invention shown more
clearly in FIGS. 2 and 2a. In the present connection, main beam 20,
shown in cross section, extends longitudinally in a ceiling grid.
Identical connectors 21 and 22 have been stabbed through a slot 23
in the web 25 of the main beam 20 and interconnect. The connectors
21 and 22 are connected respectively to cross beams 26 and 27 by
rivets at 28.
In the connection, the following occurs: (1) End 30 of connector 21
engages detent 31 to form a connector-to-connector connection, as
does end 32 of connector 22 engage detent 33; (2) Locking latches
40 on connector 21 and connector 22 are in an unflexed position;
(3) Backstops 35 and 36 on connectors 21 and 22 secure the ends 30
and 32 in the connector-to-connector lock; and (4) Connectors 21
and 22 are kept laterally and vertically constrained within slot 23
by the cross sectional configuration of the connectors, as well
known in the art. The general configuration so far described
conforms to the prior art.
In making the connection shown in FIGS. 1 and 1a, and in the cited
patents, a first connector, either connector 21 or 22, both being
identical, is thrust or stabbed through the slot 23 in the prior
art manner. In this explanation, it will assume connector 21 is
first thrust through the slot.
Locking latch 40 contacts side of slot 23 and is flexed enough to
allow the latch 40 to pass through slot 23 and reflex back to a
rest position, in a one way movement. In this position, the first
connector 21 through the slot is retained within the slot 23.
The second connector 22 is then thrust through the slot 23 along
side the first connector 21 through the slot 23. Again, locking
latch 40 contacts side of slot 23, but now there is less room in
the slot because a connector has already been inserted. The second
connector 22 into the slot, as it is thrust through the slot 23,
flexes the latch 40 toward a closed position, until the latch
passes through the slot after which it flexes open to a rest
position. The connectors 21 and 22 also form a
connector-to-connector lock at this point, as seen in FIG. 1,
wherein the detents 31 and 33 and the beam ends 30 and 32 have
flexed and then reflexed into a locked position, at rest.
In these stab-in connections, as the second connector into the
slot, for instance connector 22, travels through the slot 23 to a
seated position, after the first connector 21 into the slot has
been inserted, the following occurs: (1) The second connector 22 is
adjusted vertically within the slot 23. (2) The second connector 22
is forced laterally by a side of the slot 23 against the first
connector 21. (3) The locking latch 40 on the second connector 22
is flexed toward a closed position by a side of the slot 23 until
the latch 40 passes through the slot 23, and then it springs open
to a rest position as seen for instance in FIG. 1. (4) The locking
detents 31 and 33 and connector ends 30 and 32 on the first and
second connectors 21 and 22 are flexed apart as they contact one
another, and then reflexed into a locking position.
In the prior art, (1) through (4) above overlapped or occurred
virtually simultaneously, so that the force and work required to
complete a connection 10 was not only the sum of the forces
necessary to overcome the sum of the individual resistances created
by (1), (2), (3) and (4) referred to immediately above, but also
the force and work to overcome the friction created when forces
(1), (2), (3) and (4) overlapped, or occurred simultaneously. These
frictional resistances included: a. The friction between the latch
40 on the second connector 22 and the side of the slot 23 as the
second connector 22 was being positioned vertically in the slot 23.
b. The friction laterally between the base of the connectors 21 and
22. c. The friction between the top or bottom of the second
connector 22 and the top or bottom of the slot 23 as the second
connector 22 was being positioned vertically within the slot 23. d.
The friction between the detents 31 and 33 and ends 30 and 32 on
the first connector 21 into the slot and second connector 22 into
the slot 23 as the second connector 22 was being vertically
positioned within the slot 23.
In the prior art, in an attempt to reduce the total force and work
required, the taper 37 or slope on the leading edge of a prior art
connector 15, as seen in FIG. 3, was made at a gradual incline, so
the frictional forces could be spread throughout the length of the
insertion, as the second connector into the slot 23 was being
adjusted vertically.
The Present Improvement
The present improvement reduces substantially the force necessary
to overcome the resistance from the frictions (a), (b), (c) and (d)
above and the forces necessary in (3) above to flex the locking
latch 40 of the invention toward a closed position, and in (4)
above to flex the detents 31 and 33 and ends 30 and 32 relative to
one another to create the connector-to-connector interlock.
As in the prior art, in the present improvement the cantilevered
leaf spring latch 40 continues to be formed, as by punching, from
the connector base 39, as seen, for instance, in FIGS. 2 and 2a.
The latch of the prior art, designated 10 as seen in FIGS. 3 and
3a, is in the form of a straight lever 11, pivoted at 12. It forms
an acute sharp angle with the base 13 of prior art connector
15.
In the improvement of the invention, the latch of the invention 40,
as seen in FIGS. 2 and 2a, herein, is formed from the base 41 with
a radius 42, for instance 0.04 inches, before extending in straight
lever fashion. The straight portion 43 of the latch of the
invention 40 forms an angle of about 42.degree. with the base 41.
Such a curve in locking latch 40 increases the distance 46 the
second connector 21 or 22, enters into the slot 23 before it
contacts the side of the slot 23 at 47 to create a resistance from
such latch of the invention 40 against the side of the slot 23.
Such a curved locking latch of the invention 40 also reduces the
distance 48 the latch of the invention 40 is in contact with the
side of the slot 23 as it is being flexed toward a closed position
as it passes through the slot 23, since it contacts the latch 40
closer to the end of the latch than does prior art straight latch
10.
Representative dimensions for the locking latch 40 of the invention
are shown in FIG. 2a.
Further, the first contact of the latch of the invention 40 with
the side of the slot 23 is further out from the point 51 of the
latch of the invention 40 where it is joined to on the base 41,
since part of the curved part of the latch of the invention 40
extends in the plane of the base 41 and is not exposed to contact
by the side of the slot 23. Point 51 is the cutting start and the
bending start of the latch of the invention 40 as seen in FIG.
2a.
Thus, the force exerted by the side of the slot 23 as the latch of
the invention 40 passes through the slot is applied further from
the pivot point 51 than in the prior art, thus requiring less force
to pivot the latch of the invention 40, than in the prior art
straight lever latch 10, since the force has a greater lever arm in
the latch of the invention 40 when it meets the side of slot 23 as
it is thrust into the connection.
Thus, less force over a shorter distance is required to collapse
the latch of the invention 40 than was required to collapse latch
10 in the prior art. This results in substantially less work that
has to be done to make a connection. This beneficial effect in one
connection, is multiplied by the many connections required in
forming a ceiling grid for a suspended ceiling.
In the connection improved by the present invention, during the
time the connector is being inserted, it is necessary to adjust the
connector vertically, so that when fully inserted, the connector
fits vertically into the slot 23.
Since the force necessary to collapse the latch 10 of the prior art
was substantial, and arose near the leading edge of the connector,
the taper that guided the connector vertically to its fully seated
position so that the connector was in place vertically when fully
inserted, was gradual, to limit the added resistance at any one
point in the insertion.
Thus, even when the connector-to-connector interlock was being
created, wherein the detents were flexing, the connector was still
being adjusted vertically, in view of such necessity to make the
taper gradual rather than abrupt, thereby creating still more
resistance.
In the present invention, the taper 38 at the leading edge of the
connector 21, 22 is made relatively abrupt, at a steeper angle, so
that a relative immediate adjustment is made vertically to the
connector as it is being inserted into the slot 23. Even though a
more steep, immediate adjustment would normally require a greater
insertion force than that of a gradual insertion, there is less,
rather than more force required. This reduction in force is
obtained by the delayed contact of the locking latch of the
invention 40 with the side of slot 23, since there is virtually no
drag or resistance from the locking latch of the invention 40.
There is a further benefit that is achieved by early vertical
positioning of the connector within the slot 23 during insertion.
As the detents 31 and 33, and the ends 30 and 32 of the first and
second connectors of the invention 20 and 21 come into contact, the
detents and ends are at a position relative to one another,
vertically, where there is least resistance to flexing of these
elements laterally into the locking position. Whereas in the prior
art, contact was made between detents and ends, and force was
exerted between these elements, off-center from their most flexible
position, the force required to flex the detents and ends, was
again substantial.
FIGS. 3 and 3a show a prior art connector, while FIGS. 2 and 2a
show a connector with the improvement of the invention.
As seen in FIGS. 3 and 3a, prior art latch 10 in the form of
straight lever 11, is pivoted at an acute angle to base 13 of a
prior art connector 15. Dotted line 17 represents, in the enlarged
portion, the side of slot 23 as the connector 15 of the prior art
is inserted into the slot 23. The prior art connector 15 travels
the distance at 16 before it encounters the side of the slot at 19,
which is at a distance 18 from the end of the prior art latch
10.
In FIGS. 2 and 2a, there is shown the connector of the invention
22, which is identical to the connector of the invention 21, with
the latch of the invention 40. Again, as in FIG. 3a, dotted line 17
in the enlarged portion, represents the side of slot 23 as the
connector 22 is inserted into the slot 23. The connector 22 travels
the distance 46 before it encounters the side of the slot 23 at 47.
This is a distance 48 from the end of the latch of the invention
40.
The benefits of the present improvement over the prior art are
shown graphically in FIGS. 4a, 4b, and 4c.
FIG. 4, including 4a, 4b, and 4c, shows the resistances encountered
in a prior art connection compared to the forces encountered in a
connection with the improved connector of the invention.
In the prior art, the line from 80 to 81 represents the resistance
encountered during the initial insertion of the second connector
into the slot, while the latch 10 is being flexed from its initial
contact with the side of the slot 23, until the resistance reaches
its highest at about 27 pounds at point 81.
The contact of the straight lever 11 of prior art latch 10 is
relatively close to the pivot 12 during this travel. At 81, there
is a drop off in resistance during travel to point 82 to about 10
pounds. The straight lever latch 10 of the prior art during this
drop off, contacts the side of the slot 23 further out along its
straight lever 11, as it travels through the slot 23, so less force
is necessary, since the lever arm is longer than at the initial
contact.
At 82 there is a rise again in resistance due to the flexing of the
detents 31 and 33 and connector ends 30 and 32 while they are
forming a connector-to-connector lock. The resistance rises to
point 83 at which point the connector-to-connector lock is
completed, and all elements have reflexed to a rest position with
no further resistance or movement occurring.
The forces required to overcome the resistance encountered in
making a connection with the improvement of the invention is shown
graphically in FIG. 4a. The same movement of the second connector
22 into the slot 23, having the latch of the invention 40, is
shown, as was shown with the prior art connector, in FIG. 4a.
Initial contact with the side of the slot 23 occurs at 90 and rises
to 91 where there is a resistance of about 14 pounds. There is a
very slight drop off in resistance as the latch of the invention 40
passes through the slot. The resistance then rises to point 93 at
about 16 pounds while the connector-to-connector lock is being
formed as the detents 31 and 33 and connector ends 30 and 32 are
flexing, after which there is a drop off at point 94, where all
resistance ends after the connector-to-connector lock is
formed.
The force necessary, and the distance over which the force must be
applied, is obviously remarkably less, in making the connection,
with the present improvement in the connector.
FIG. 4c overlaps the charts of FIGS. 4a and 4b, with the locked
position of the prior art connection, and the connection of the
invention as an overlapped common point along the horizontal axis
at 96. .DELTA.X in the chart represent the distance of the delay in
contact between the prior art latch 15, and the latch of the
invention 40, with the side 17 of the slot 23, as the second
connector into the slot is being inserted. Again, FIG. 4c, in chart
form, represents the substantial reduction in force, and work
necessary to make the present connection, over that to make the
prior art connection.
* * * * *